[nine_k]

I'm 100% on board regarding the use of pure functions and eschewing shared mutable state wherever practical. (Local mutable state is fine.)

But OOP does not necessitate mutable state; you can do OOP with immutable objects and pure methods (except the constructor). Objects are collections of partially-applied functions (which is explicit in Python) that also conceal internal details within its own namespace. It is convenient in certain cases.

[adamzwasserman]

I agree. I sometimes do that.

But very rarely.